Home Improvement Questions? Ask a Handyman for Answers ASAP
The very first thing to do is take good photographs in good light.After that, contact your building insurance company - they will guide you in what to do. For example, they may ask you to obtain two (or three) quotations from builders who can advise on the problem. If the remedial work is substantial then they might provide their own contractors. They might well send a surveying company to install visible markers that allow them to accurately monitor the width of the crack.Also, start and keep an accurate diary of events, including each time that you contact the insurance company or anyone else.